Salut!
[tex]a = 33 \times 3 {}^{30} + 7 \times {3}^{31} + 3 {}^{33} \\ a = 3 {}^{30} (33 + 7 \times 3 + 3 {}^{3} ) \\ a = 3 {}^{30} (33 + 21 + 27) \\ a = 3 {}^{30} \times 81 \\ a = 3 {}^{30} \times 3 {}^{4} \\ \red{a = {3}^{34} = (3 {}^{17} ) {}^{2} } \\ \red{ \boxed{a \: este \: patrat \: perfect}}[/tex]
